基于周期Choi-Williams Hough变换的线性调频连续波信号参数估计算法

Parameters Estimation Algorithm of Linear Frequency Modulated Continuous Wave Signals Based on Period Choi-Williams Hough Transform

在采用联合CWH(Choi-Williams Hough)变换估计多周期线性调频连续波(LFMCW)信号的参数时,当观察时间大于一个周期时,输出信号的信噪比不再随时间的增加而增大,且时频图中会出现多个峰值干扰信号参数的估计。结合CWH对LFMCW信号的能量聚集和相干累积思想,该文提出一种基于周期CWH变换的多周期LFMCW信号的参数估计算法,给出了多周期LFMCW信号的PCWH变换公式;分析了PCWH输出信噪比与观测时间和观测样本信噪比的关系;分析了参数估计精度。最后,数值仿真验证了该算法的有效性,证明在对多周期LFMCW信号参数估计时,PCWH更优。

When using a Choi-Williams Hough （CWH） transform to estimate the parameters of the Linear Frequency Modulated Continuous Wave （LFMCW） signals, the signal observation time is longer than a period, the output SNR at the true parameter value does not increase with the observation time increasing and there are multiple peaks in the time-frequency image. In virtue of the energy congregation of CWH for LFMCW signals and the coherent integrator in signal processing, a multiple period LFMCW signals parameters estimation method based on period CWH （PCWH） is studied. Firstly, the PCWH formula of the multiple period LFMCW signals is given. Then the relationship among the output SNR of PCWH, the observation time and the sample signal SNR is analyzed. Finally, the estimation accuracy formula of PCWH is derived. The numerical simulation shows that the effectiveness of the proposed method and the PCWH is superior to CWH for estimating a multiple periods LFMCW signal.